This invention is directed to liquid foliar hormonal products that are designed for use in low water volume sprayers. Foliar feeding of plants presents many technical challenges. Plants put up many barriers to the retention, entry, and transport of active agents such growth inhibitors and stimulators. In addition, environmental conditions and plant factors (age, architecture, leaf morphology and leaf arrangement) may decrease the activity of a plant modulator. Adjuvants are commonly used to improve a plant modulator performance.
The use of liquid fertilizers and hormonal blends, foliarly applied, on professionally managed turf is shown in U.S. Pat. No. 5,188,655. The '655 patent addresses the proper blends of gibberellic acids (GA), auxins (AUX) and cytokinins (CYT) to optimize plant growth. Proper blending of the hormonal components must be combined with proper application to the turf to ensure optimum growth and health. Therefore, all foliar products utilizing the stated hormonal blend must be used in traditional commercial sprayers that can maintain a recommended spray volume of 25-40 gallons per acre (GPA). A standard commercial spray rig has a 100 to 150 gallon tank mounted to the frame. This permits numerous nutritional and hormonal products to be added to the tank without incident because of the high degree of dilution.
But, based on the evidence of increasing environmental regulations, particularly water usage and runoff, manufacturers of spray rigs are redesigning their equipment to use ultra-low volumes of water. In some instances the equipment discharges water volumes in the 2-4 gibberellic acid range while tank sizes range from 8 to 14 gallons. This technology is known as the “Controlled Drop Applicator” (CDA). U.S. Pat. No. 4,619,401, provides an example of the newly designed spray nozzles that are required to provide these ultra-low water volumes. The design of these nozzles makes it imperative that the liquid formulations passing through this orifice do not contain rigid particulates or other components that will cause clogging. Because of the low-volume tanks and low spray rates, only one or two nutritional and hormonal products can be added at one time. However, as many as twenty different nutrients and hormones are needed for proper plant growth, thus multiple spray applications must be made to adequately cover the agronomic needs of the plant. This is not practical because of the demands of a golf course or sports stadium.
The manufacturers of liquid foliar fertilizers and hormonal products are now challenged to redesign their products to comply with the trend toward these ultra-low spray volumes. This is not a straight-forward exercise, as the chemical limitations do not allow concentrating these products by 10-fold. Furthermore, higher concentrations of products increase the likelihood of particulate formation and increased chance for clogging of the nozzles.